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  • 23 Oct 2017
    The heat loss through junctions is known as thermal bridging and can be one of the most significant sources of heat loss within a building. In a building which has poor insulation, thermal bridging will be less significant, but in a modern new building, that has a highly insulated fabric, the heat will pass through these junctions much faster relative to the surrounding materials. While these junctions cannot be eliminated, properly designed details can drastically reduce this effect. It’s absolutely critical we understand the heat loss through these important parts of a building and use a qualified assessor to calculate the PSI value of a junction to better inform the design. The effect of thermal bridging can vary drastically between buildings depending on design, with anywhere between a realised 5-50% of a building’s heat loss coming through these thermal junctions. The rate of heat loss between these thermal junctions is measured as a PSI values (pronounced ‘si’). Calculating them will make the thermal model much more accurate and feed back into the design creating a real difference to the end client and in terms of energy savings, or even more floor area if radiators don’t need to be as big.  When standardised details are being used, the cost for each individual PSI value across each building is exceptionally low in comparison to other options. The value the client gains from putting in the calculated PSI values is extremely cost effective.  So, in situations where developers are using the same corner detail on several projects (i.e five houses in one location), it starts to add up quickly. SAP calculation methodology assumes default values that are very poor or estimates how much heat is going through those areas. By calculating that specific PSI value, you are actually measuring how much heat is going through at that point. The assessor can input and overwrite that poor value with something that’s realistic and can make 5-10% and sometimes 15% of carbon savings for the entire building.  On a standard detached or terraced house, the assessor can expect to make 5-6% carbon savings over ACDs. If the thermal junctions are not measured, then a default PSI Value is applied to the calculation. The problem in the industry is these default values or dated sets of values such as Accredited Construction Details (ACDs) and Enhanced Construction Details (ECDs) can be inaccurate.  At Darren Evans Assessments we will carry out an independently assessed thermal model to cover all of the places where the default values or ACD values are worse than in reality. As a PSI value assessor, we are essentially tightening down the design and making it more accurate by inputting correct and supported heat loss calculations.  This improved accuracy in the building model will lead to design improvements.  By taking the time to look at and feed that specific information into the calculation, the assessor is able to provide advice on how to help build these details. While there are some in the industry who create thermal models that are completely unbuildable, we are able to come on board and simplify the whole thing to make sure it is correct.  Independently assessed PSI Values will always be cost effective on every medium scale and larger residential development. When you have more than 10 units employing these details (over even multiple sites with standard details), the larger design and build contractors can focus too much on big ticket items such as expensive renewables and thermal bridging can be overlooked. If you can make a difference over whether or not the PV sits on the roof, the small cost to do the PSI value calculations versus, say, £70k worth of PV, would seem like a no-brainer. If you are not using independently assessed PSI Values in your SAP calculation you are five or 10 years behind everyone else. By Brandon Wipperfurth, Sustainability and Energy Consultant Visit: https://www.darren-evans.co.uk/
    0 Posted by Talk. Build
  • The heat loss through junctions is known as thermal bridging and can be one of the most significant sources of heat loss within a building. In a building which has poor insulation, thermal bridging will be less significant, but in a modern new building, that has a highly insulated fabric, the heat will pass through these junctions much faster relative to the surrounding materials. While these junctions cannot be eliminated, properly designed details can drastically reduce this effect. It’s absolutely critical we understand the heat loss through these important parts of a building and use a qualified assessor to calculate the PSI value of a junction to better inform the design. The effect of thermal bridging can vary drastically between buildings depending on design, with anywhere between a realised 5-50% of a building’s heat loss coming through these thermal junctions. The rate of heat loss between these thermal junctions is measured as a PSI values (pronounced ‘si’). Calculating them will make the thermal model much more accurate and feed back into the design creating a real difference to the end client and in terms of energy savings, or even more floor area if radiators don’t need to be as big.  When standardised details are being used, the cost for each individual PSI value across each building is exceptionally low in comparison to other options. The value the client gains from putting in the calculated PSI values is extremely cost effective.  So, in situations where developers are using the same corner detail on several projects (i.e five houses in one location), it starts to add up quickly. SAP calculation methodology assumes default values that are very poor or estimates how much heat is going through those areas. By calculating that specific PSI value, you are actually measuring how much heat is going through at that point. The assessor can input and overwrite that poor value with something that’s realistic and can make 5-10% and sometimes 15% of carbon savings for the entire building.  On a standard detached or terraced house, the assessor can expect to make 5-6% carbon savings over ACDs. If the thermal junctions are not measured, then a default PSI Value is applied to the calculation. The problem in the industry is these default values or dated sets of values such as Accredited Construction Details (ACDs) and Enhanced Construction Details (ECDs) can be inaccurate.  At Darren Evans Assessments we will carry out an independently assessed thermal model to cover all of the places where the default values or ACD values are worse than in reality. As a PSI value assessor, we are essentially tightening down the design and making it more accurate by inputting correct and supported heat loss calculations.  This improved accuracy in the building model will lead to design improvements.  By taking the time to look at and feed that specific information into the calculation, the assessor is able to provide advice on how to help build these details. While there are some in the industry who create thermal models that are completely unbuildable, we are able to come on board and simplify the whole thing to make sure it is correct.  Independently assessed PSI Values will always be cost effective on every medium scale and larger residential development. When you have more than 10 units employing these details (over even multiple sites with standard details), the larger design and build contractors can focus too much on big ticket items such as expensive renewables and thermal bridging can be overlooked. If you can make a difference over whether or not the PV sits on the roof, the small cost to do the PSI value calculations versus, say, £70k worth of PV, would seem like a no-brainer. If you are not using independently assessed PSI Values in your SAP calculation you are five or 10 years behind everyone else. By Brandon Wipperfurth, Sustainability and Energy Consultant Visit: https://www.darren-evans.co.uk/
    Oct 23, 2017 0
  • 17 Sep 2017
    In a world of global warming, environmental regulations and our quest for a more sustainable built environment, Life Cycle Assessment (LCA) is clearly here to stay. A method for evaluating and measuring a product’s environmental impact during their lifecycle from cradle to grave, the LCA of products used in construction enables specifiers to make informed decisions about the comparative environmental impacts as well as the cost and durability of rival products. This is as crucial in the choice of industrial flooring as in any other sector.    Faced with daunting 2050 greenhouse gas reduction targets, Life Cycle Assessment (LCA) is increasingly recognised by the construction industry as the most credible and comprehensive method for assessing and comparing the environmental impacts of products over their entire life cycle. For the specifier, an LCA is a useful tool, enabling them to compare quantitative data on products and systems’ sustainability against an accepted method of measurement. It may mean that two competing products which have similar performance may have very different LCA scores, which will mean a specifier is able to deliver the performance needed but also increase their sustainability credits. This can be particularly beneficial where projects require green certification such as those with BREEAM requirements within their planning permission. The European standard EN 15804, which governs Environmental Product Declarations, includes eight impact categories which must be covered by LCAs. Of these, three are deemed particularly relevant for flooring: Cumulative Energy Demand (CED) - the total amount of primary energy consumed by a product from renewable and non-renewable resources. Global Warming Potential (GWP) - The product’s potential contribution over its life cycle to climate change, focusing on emissions of greenhouse gases, such as CO2 (also known as ‘carbon footprint’) Photochemical Ozone Creation Potential (POCP), or “summer smog” - the formation of reactive chemical compounds, e.g., ozone, by the action of sunlight on volatile organic compounds (VOCs) and nitrogen oxides (NOx). Sika evaluates products systematically on environmental performance via regular and comprehensive LCAs according to ISO 140040 which describes the principles and framework for LCA, as well as EN 15804. The company undertakes LCAs from both a Cradle to Gate and Cradle to Grave perspective, the former seeing most of the environmental impacts connected to the raw materials used and the latter seeing most impacts in the in-use and end-of-life phases. The impacts in these phases will be highly dependent on the different maintenance and refurbishment requirements over the life-cycle, which are in turn highly dependent on a floor’s intended use. To make life easier when specifying products, Sikafloor has developed an Eco Tool at its Swiss Research Institute which will quickly and easily provide customers with LCA information on a specific product as well as useful Total Cost of Ownership (TCO) information projected over the life of a product, from Cradle to Grave. In addition to the LCA of a product, the Eco Tool will provide details to specifiers, architects and building owners of a product’s whole service life, including transport impact, application cost, cleaning costs and other operational costs. The tool also enables comparison between products and against various sustainability and operational criteria, to enable an informed decision to be made. A new family of hybrid industrial flooring systems, called PurCem® Glossy, harnesses polyurethane cement hybrid technology to also provide strong eco credentials. As well as the essential moisture tolerance, toughness and chemical resistance characteristics needed for industrial sector projects, the flooring’s LCA, undertaken by Sikafloor, shows it has a lower CED over a 15-year lifetime compared with other flooring technologies.  In addition its very low VOC emissions have seen PurCem® Glossy gain AgBB approval in accordance with ISO standards. Ideal in industrial applications such as food and beverage dry and wet areas, chemical plants and warehouses, the durability of Purcem Glossy is a key part of its sustainability. No refurbishment is needed to prolong its durability over 15 years; plus it is a solvent-free solution that allows application close to on-going production process areas. This means that repair and renovation of existing floors can be undertaken without shutting down the plant or production lines. Sika Flooring has put a major focus on using less energy and resources when compared with other technologies and systems to help meet green goals as a society.  This means offering a lower Global Warming Potential (carbon footprint) and low or even zero VOC options to deliver health benefits for both public and private sector buildings.  visit www.sika.co.uk.
    0 Posted by Talk. Build
  • In a world of global warming, environmental regulations and our quest for a more sustainable built environment, Life Cycle Assessment (LCA) is clearly here to stay. A method for evaluating and measuring a product’s environmental impact during their lifecycle from cradle to grave, the LCA of products used in construction enables specifiers to make informed decisions about the comparative environmental impacts as well as the cost and durability of rival products. This is as crucial in the choice of industrial flooring as in any other sector.    Faced with daunting 2050 greenhouse gas reduction targets, Life Cycle Assessment (LCA) is increasingly recognised by the construction industry as the most credible and comprehensive method for assessing and comparing the environmental impacts of products over their entire life cycle. For the specifier, an LCA is a useful tool, enabling them to compare quantitative data on products and systems’ sustainability against an accepted method of measurement. It may mean that two competing products which have similar performance may have very different LCA scores, which will mean a specifier is able to deliver the performance needed but also increase their sustainability credits. This can be particularly beneficial where projects require green certification such as those with BREEAM requirements within their planning permission. The European standard EN 15804, which governs Environmental Product Declarations, includes eight impact categories which must be covered by LCAs. Of these, three are deemed particularly relevant for flooring: Cumulative Energy Demand (CED) - the total amount of primary energy consumed by a product from renewable and non-renewable resources. Global Warming Potential (GWP) - The product’s potential contribution over its life cycle to climate change, focusing on emissions of greenhouse gases, such as CO2 (also known as ‘carbon footprint’) Photochemical Ozone Creation Potential (POCP), or “summer smog” - the formation of reactive chemical compounds, e.g., ozone, by the action of sunlight on volatile organic compounds (VOCs) and nitrogen oxides (NOx). Sika evaluates products systematically on environmental performance via regular and comprehensive LCAs according to ISO 140040 which describes the principles and framework for LCA, as well as EN 15804. The company undertakes LCAs from both a Cradle to Gate and Cradle to Grave perspective, the former seeing most of the environmental impacts connected to the raw materials used and the latter seeing most impacts in the in-use and end-of-life phases. The impacts in these phases will be highly dependent on the different maintenance and refurbishment requirements over the life-cycle, which are in turn highly dependent on a floor’s intended use. To make life easier when specifying products, Sikafloor has developed an Eco Tool at its Swiss Research Institute which will quickly and easily provide customers with LCA information on a specific product as well as useful Total Cost of Ownership (TCO) information projected over the life of a product, from Cradle to Grave. In addition to the LCA of a product, the Eco Tool will provide details to specifiers, architects and building owners of a product’s whole service life, including transport impact, application cost, cleaning costs and other operational costs. The tool also enables comparison between products and against various sustainability and operational criteria, to enable an informed decision to be made. A new family of hybrid industrial flooring systems, called PurCem® Glossy, harnesses polyurethane cement hybrid technology to also provide strong eco credentials. As well as the essential moisture tolerance, toughness and chemical resistance characteristics needed for industrial sector projects, the flooring’s LCA, undertaken by Sikafloor, shows it has a lower CED over a 15-year lifetime compared with other flooring technologies.  In addition its very low VOC emissions have seen PurCem® Glossy gain AgBB approval in accordance with ISO standards. Ideal in industrial applications such as food and beverage dry and wet areas, chemical plants and warehouses, the durability of Purcem Glossy is a key part of its sustainability. No refurbishment is needed to prolong its durability over 15 years; plus it is a solvent-free solution that allows application close to on-going production process areas. This means that repair and renovation of existing floors can be undertaken without shutting down the plant or production lines. Sika Flooring has put a major focus on using less energy and resources when compared with other technologies and systems to help meet green goals as a society.  This means offering a lower Global Warming Potential (carbon footprint) and low or even zero VOC options to deliver health benefits for both public and private sector buildings.  visit www.sika.co.uk.
    Sep 17, 2017 0